An image forming apparatus includes an image forming unit which forms a toner image on a print medium, and a fixing device which fixes the toner image to the print medium by applying heat and pressure to the print medium. The fixing device may include a thermal-type fixing device. The fixing device may include a fixing member to move a print medium, a pressing member forming a fixing nip portion, and a heating member including heat generators, which generate heat when currents are supplied thereto and which are arranged in a main scanning direction, and heat the print medium via the fixing member. The fixing device heats the heat generator of the heating member in synchronization with the timing when the print medium with the toner image formed therein passes through the fixing nip portion.
The image forming apparatus may be able to perform printing on various kinds of print media. Depending on various print media, the temperature rising rate may be different even though the quantity of heat provided from the heating member is equal. Therefore, depending on the print medium, it may not be possible to obtain a fixing temperature, which is a temperature sufficient to fix the toner image at timing when the print medium passes through the fixing nip portion.